FIG. 1 shows a capacitive in-cell touch display panel comprising an array substrate 40 and an upper substrate 50 opposed to the array substrate 40, an upper polarizing sheet 60 is disposed on the upper substrate, touch driving electrodes 43, gate lines 41, and common electrodes 42 are provided on the array substrate 40, the touch driving electrodes 43 and the common electrodes 42 are arranged on a same layer and disposed with intervals, touch sensing electrodes 20 are provided on the inner surface (i.e. the surface facing towards the array substrate) of the upper substrate 50, the common electrode 42 corresponds to the touch sensing electrode 20. When the operator's finger does not touch the upper surface of the touch display panel, the touch sensing electrodes 20 receive electric field lines from the touch driving electrodes 43. When the operator's finger touches the upper surface of the touch display panel, the electric field lines emitted from the touch driving electrode 43 beneath the touch point are attracted to the operator's finger, the capacitance beneath the touch point is caused to change, thereby the coordinate of the touch point can be determined based on the change of the capacitance.
With the increasing requirements of operators to the touch sensitivity, how to improve the sensitivity of the finger touch becomes a technical problem to be solved in the present field.